The correct option is C 1
A1,A2,G1,G2 and H1,H2 are two A.Ms, G.Ms and H.M.s between a and b.
a,A1,A2,b are in AP ⇒A1+A2=a+b
a,G1,G2,b are in GP ⇒G1G2=ab
a,H1,H2,b are in HP ⇒1H1+1H2=1a+1b
Hence, option C.